Several methyl-substituted cyclopropanecarboxylates were prepared and their steric configurations were established. The insecticidal activity against the housefly of their 5-benzyl-3-furylmethyl esters were tested. Among the substituents on cyclopropane ring, cis-methyl group to ester linkage has been found to be the most essential part for toxicity and trans-methyl and trans-isobutenyl groups greatly enhance its toxic activity.
